Imagery taken by satellites, planes and other sources has long been used to provide visual information about the earth. Recently, dramatic improvements in computer processing power and broadband streaming technology have led to the development of interactive systems for navigating imagery (e.g., map imagery). Some interactive map navigation systems provide a user interface (“UI”) with navigation controls for dynamically navigating cities, neighborhoods and other terrain in three dimensions. The navigation controls enable users to tilt, pan, rotate, zoom and activate terrain and buildings for different perspectives at a point of interest. An example of an interactive 3D map system for navigating Earth imagery is Google Earth™ developed by Google Inc. (Mountain View, Calif.).
The production imagery used by interactive map navigation systems is typically derived by processing large pieces of geo-located imagery or “assets.” Such assets can be taken from a single pass of a satellite, airplane or other airborne platform, or can be stitched together from multiple aerial images. Once the assets are processed, they can be moved to datacenters where it can be distributed to client devices.
Different assets may have different resolutions and/or may be captured at different points in time. At some points in time, assets may not be available at particular resolutions. Accordingly, for such points in time, a viewing field may include only the assets available at the specified resolution. This may result in blank spaces in the viewing field, or an inability to view any of the assets for such points in time at the specified resolution.